For an anode of a capacitor element constituting a solid electrolytic capacitor, metals having an insulating oxide film forming capacitance, such as aluminum, titanium, niobium, zirconium, and tantalum, i.e., so-called valve metals, have conventionally been in use. The surface of such a valve metal is anode-oxidized, so as to form an insulating oxide film. Then, an solid electrolyte layer substantially functioning as a cathode is formed, and a conductive layer made of graphite, silver, or the like is provided as a cathode, whereby a capacitor element is obtained. A part of the capacitor element is constituted by a storage part in a rectangular thin strip form having a surface formed with the cathode, and a plurality of pairs of thin strip-like electrode parts projecting outward from a side face of a longer side of the storage part and functioning as an anode. A capacitor element having such a form is disclosed in U.S. Pat. No. 5,880,925, for example. The capacitor element in accordance with the above-mentioned publication is one employed for a laminate type ceramic capacitor.
The inventors conducted diligent studies concerning solid electrolytic capacitors such as the one mentioned above, and have found that lower ESL can be achieved when drawing out a plurality of anodes and cathodes of the capacitor element by branching (i.e. multitermination). Further, expecting that further multitermination can be attained by arranging a plurality of capacitor elements having such a form in a row, the inventors have newly found a technique which can significantly lower the ESL of the solid electrolytic capacitor.
That is to say, it is an object of the present invention to provide a solid electrolytic capacitor whose ESL is significantly lowered.